Tire gauge



L I. GLICKERMAN. TIRE GAUGE. Armcnlon men Dems. 1919.

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Patented May 23, 1922. y

Uliilllflqq El ritirarsi JACOB l. GLCKERMAN,OF CHICAGO, ILLXNOIS.

Application filed December 29, .1919.

T 0 all whom t may concern.'

Be it known that l, JAooe l. GLIGKERMAN, citizen ot the United States, residing at Chii cago, in the county ot Cook and State oit Illinois, have invented certain new and useful Improvements in a Tire Gauge; and l do hereby declare the following to be a full, clear, and exact description ci the invention. such as will enable others'skilled in the art to which it appertains to make and use the same. Y

My invention relates to pressure gauges. its general objects including the providing of an unusually simple and compact type of gauge. More particularly, my invention relates to the class of pressure gauge adapted for use in ascertaining the air pressure in pneumatic tires. For this purpose, my invention aims to provide a simple, inexpensive and compact gauge which will 4retain its initial size at all times and therefore will not have any projecting parts which might interfere with the convenient attaching and detaching of the gauge; to provide a novel mechanism whereby the indication of the gauge can readily beY ascertainedwithout requiring needles, gearing or otherdelicat-eA parts; to provide simple 'and releasable means for causing the gc uge to hold its indieating position when detached from the tire or other source of pressure; and also desirably to provide a simple substitute tor the pistons or other packings, commonly employed in such pressure gauges. Still iurther objects will appear from the following specification and from the acompanying drawings, in which- Fig. 1 is a side elevation oi a gauge em-.

bodying my invention and designed tor use as a tire gauge.

Fig. 2 is a longitudinal and vertical section taken alongthe center line of Fig. 1.

Fig. -3 is a horizontal and central section taken along the correspondingly numbered line of Fig. 2.

Fig. 4f. is a front elevation oil another' embodiment of my invention, namely one in which the indications 'are read from the Aflat face of the casing, with a part of the casing cut away to show the indicating strip.

Fig. 5 is an enlarged fragmentary section taken along the correspondingly numbered line of Fig. 2 and showing the spring which acts as a ratchet pawl.

Fig. 6 is a section similar to Fig. 2, show- -used on tires. packing ring 5 disposed in its mouth so as to 'man eenen.

Serial No. 347,995.

ing another embodiment ot my invention, namely one not employing a flexible tube.

ln the embodiment ot 1. 2 and B, the gauge of my invention includes a shallow and substantially cylindrical casing comprising a main part 1 and a cover The main portion 1 of the casing has a threaffied inlet B screwed into a nipple il, which nipple is designed to slip over the inlet ot the valve as rThe nipple Il: has a rubber aiiiord a joint when slipped upon the tire valve in the usual manner, and also has suitable means, such as a bent pin 6 adapted to engage the stem ot 4the tire valve so as to open this valve when the gauge ol' my invention is set in operative position upon the valve.

Rigidly secured to the body l. ot the casing is a shaft 'r' which is slotted to interlock with the inner'end ot a spiral spring 8. This spiral spring is wound around the shaiit and has its outer end 9 hooked through a slot in a drum 10 which is itree to rotate on the shaft 7. Fastened to this drum 10 (as by soldering) is a cup 11 which 'forms a tight sealing head for one en d of a soft rubber tube 12. This rubber tubing extends in the space between the drum 10 and the cylindrical wall ot the casing portion l., somewhat aitter the manner shown in Fig. l. and the lower end of' the tubeis desirably dared and clamped between the threaded inlctB of the casing and the nipple 4. Consequently. the flexible tube 12 forms a simple means it'or connecting the inlet of the pressure gauge with the head ll and for preventing air as admitted from the tire from reaching otherparts of the casing of my gauge. Consequently` the flexible tube 12 forms a simple means for connecting` the inlet of the pressure gauge with the head 11 and for preventing air admitted from the tire from reaching other parts of the casing of my gauge. Rigidly connected to the drum 10, as for example by being fastened to the cup l1, is an indicator strip 13 which extends past a relatively narrow opening or window 14 in the cylindrical wall ot the casing. This strip 13 carriesv a series of markings indicating various pressures.

In operation, when mygauge isaliixed to the valve stem of an ordinary tire valve in the usual manner, a relatively small part of the compressed air in the tire will enter the rubber tube 12, thereby exerting pressure against the head of the cup 11, so that this pressure will rotate the drum 10 in the direction of the arrow of Fig. 2 against the tension of the spring 8. Consequently, the

indicating strip 13 will be correspondingly moved in this same direction. so that the indication visiblethrough the window 14 will correspond to the extent of: this movement. In practice, the elasticity ot the rubber tube 12 will also tend to oppose its stretch and will therefore cooperate with the spring` S in resisting the movement ot theindicating member 13 which exposes its indications sucvcessively through the window or opening '1.4. However, t-his elasticity may vary somewhat with variations in the thickness and age ot the rubber, hence I desirablv do not depend to any material extent on the same for resisting the movement oi" the rotatable drum and the parts which are carried by this drum. Instead, I preferably depend Jfor the greater part of the resistance ou a spring. which be accurately calibrated so as to insure the desired accuracy oic the readings.

To insure a proper adjustment ot the Zero point of the pressure gauge with respect to the window7 I desirably interlock the inner end oi the spring with the shaft 7, andinterlockthisshaftwiththebody1 ot the casing after the parts have been set in place with the zero point in its desired position. In this way, I can readily allow for such variations as are apt to occur in the length of the longitudinally eXpansible tube 121 Then the cover 2 can afterwards be slipped into position.

In practice, the tire which is to be tested as. to its pressure may have its valve disposed in an inconvenient position for reading the gauge while it is applied to the valve, or the wheel may be in too dark a place for easily taking the desired reading. I therefore desirably provide suitable means for causingthe gauge to hold its pressure reading after it is detached troni the valve of the tire or from any other source ot pressure. lThis I may accomplish in any one ot numerous ways. as for example by equipping a part of the periphery of the drum 10 with ratchet teeth 20 projecting into the path oi" a spring pawl 21 which is mounted within the casing of thegauge. Then I have here shown this spring pawl in Figs. 2 and 5 as having a bend projecting through an aperture in the casing, so thatthe user oit the gauge can release the pawlby pressing inwardly on this bend', whereupon the spring 8 will return the ldrum and the indicating strip to their initialpositions. I v

From the above description and illustrati ons'it will be obvious that Jdie gauge of my invention is extremelyv simple and that since the fluid pressure only enters the bore of the elastic tube which has its free endl closed by the cup 11, I do not require the casing proper to be air-tight in construction. Furthermore, by varying the size oi the spiral spring and correspondingly varying the markings on the indicating` strip 13, I can readily adapt the gauge of my invention to considerable variations in in'essure.V Moreover7V it will be evident that although I ernploy a movable part directly connected to the iruilicating` scale. .this does not project beyond the casing ot the gauge.. hencethere is no projecting part to catch on spokes ot the wheel or to interfere withthe ready attaching or detaching of the gauge. So also. I am able to provide a dial type of gauge without employing gears. leversV or other delicate and complicated mechanisms.

Howev r. while I' have heretofore de scribed my invention in a desirable embodiment, I do not wish to be limited to the construction and arrangement thus disclosed, `it being obvious that the saine might be modified in many ways without from the spirit ot the appended claims. For example.7 instead of havingthe indicating strip 13 curved latwise into a `lormV in which it extends concentric with a portion ot' the casing as in Fig. 2., IV may employ a substantially arcuate form ot strip having its in-V dicating face parallel to one ot the dat sides ot the casing. In'that case, the window or opening 14V would be in this flat side casing. vas shown for example in Fig. 4. Nor do I wish to be limited to the use of a pressure confining tube, as some or' the novel features of my invention may be accomplished without the latter. Thus Fig. 6V shows an embodiment of my invention in which the part oi the casing behind the piston 16 is tightly sealed, the opening 14 being closedby a strip 15 ot Celluloid-or the like. In this case I employ a web 16 secured to the drum 10 and peripherally packed by a binding 17 ot leather or the like. which web-acts as a piston traveling in the annular space betweenV the drum and the cylindrical wall of the casing at one side ot the latter, .Then I tasten a similar web 18V to the casing andl pack it for slidable engagement with the drum1 and-this web'18 prevents the air pressure from reaching the other side ofV the piston 16. I/Vith this embodiment, al pin hole 19 permits the escape of air in frontof the piston. and the indicating strip 17 may be fastened' direct to the drum as shown in Fig. 6. i Y

I claim as my invention 1. In a pressure gauge, a substantially cylindrical. casing having a lateral inlet and having a relatively small opening at a distance from the inlet', a shaft axial ofi the casing, a spiral spring disposed so that it can be wound on the shat'and having its inner end locked against rotation with respect to the casing, a drum rotatable on the shalrt'and housing the spring and interlocked denarting y with the outer end of the spring, an indica tion-carrying strip test with respect to the drum and having its indicating portion adapted to moi/'e past the said opening, and means operable fluid pressure for rotating the drum against the resistance of the spring` to cause the indicating strip to more past the said opening, the said means including a substantially cup-shaped head tastened to the periphery or" the drum a nipple arranged tor securing the casing to a source of pressure, and a longitudinally expansible tube having its major portion disposed Within the casing and having one end secured to the said nipple and its other end closed by and secured to the cup-shaped head.

2. ln a pressure gaugeF a casing, a drum concentric therewith and rotatably mounted therein. a tube made of material adapted to be elongated by internal pressure disposed in single arcuate formation between the drum and the casing and respectively 'tastened at its ends to the drum and the casing; means tor connecting one end of the tube to a source oit pressure, and indicating means associated with the drum and visible `trom the exterior of the casing for indicating the elongation of the tube by internal pressure in terms of the said pressure, and ratchet means releasable from the exterior of the casing :tor latching the drum in the position to `which it is moved by the elongation of the tube under pressure) In a pressure gauge, a rotatable inemd ber, an indicator element carried by it a spring resisting the rotation ot tbe said member, an elastic tube adapted to be bodily elongated by internal pressure and so connected at its free end to the rotatable mem-- ber that the elongation of the tube by internal pressure exerted between the ends ot the tube Will rotate the said member against the resistance of the said spring., a casing housing the aforesaid elements and having` an aperture opposite the indicator element, ano ratchet means releasable from outside the casing tor latching the rotatable member in the position to which it is moved by the said pressure-eifected rotation.

fl. A pressure gauge as per claim 3, in which the ratchet means comprise ratchet teeth on the rotatable member and a spring pawl carried by the casing, the casing having an aperture affording access to the pawl for releasing the same from engagement with the ratchet teeth.

Signed at Chicago, Illinois, December 22nd, 1919.

JACOB I. GLICKERMAN. 

